Electric dry shaver

ABSTRACT

ELECTRIC SHAVER OR OTHER APPLIANCE HAVING A PAIR OF PARALLEL OSCILLATING SHAFTS OF RECTANGULAR CROSS SECTION, EACH OF THESE SHAFTS DRIVERS A SEPARATE CUTTER OR OTHER DRIVEN MEMBER. A POWER UNIT IS PROVIDED HAVING MOTOR MEANS WITH A DRIVE PROJECTION MOVABLE TOWARD AND AWAY FROM THE PARALLEL SHAFTS. A UNITARY BIFURCATED CONNECTING ROD INTERCONNECTS THE PROJECTION AND THE TWO PARALLEL SHAFTS. THIS CONNECTING ROD IS SUFFICIENTLY RESILIENT TO PERMIT FLEXING SO THAT NO BINDING OCCURS. SPRING MEANS IN THE SHAPE OF A SHORT HANDLED MULTI-TINED FORK HAVING THE HANDLE PORTION SECURED TO THE RECTANGULAR SHAFTS BIAS THE CUTTER INTO SHEARING ENGAGEMENT WITH THE PERFORATED COMB. THE COMB IS DEFINED BY TWO JOINED ARCUATE PERFORATED SECTIONS.

Jan. 19, 1971 c, BAUER 3,555,676

' ELECTRIC DRY SHAVER Original Filed May 27, 1966 3 Sheets-Sheet 1CHARLES L. BA UER 2 X fur enter Jan- 19, 1971 c, BAUER 3,555,676

ELECTRIC DRY SHAVER Original Filed May 27, 1965 5 Sheets-Sheet 2 In fanto," CHARLEJ L. BAUER QM e,

Jan. 19, 1971 c. L. BAUER ELECTRIC DRY SHAVER 3 Sheets-Sheet 3 OriginalFiled May 27. 1966 I72 fen for CHARLES L. BA (1512 B fit e.

United States Patent 3,555,676 ELECTRIC DRY SHAVER Charles L. Bauer,Columbia, S.C., assignor to Sunbeam Corporation, Chicago, Ill., acorporation of Illinois Original application May 27, 1966, Ser. No.553,393, now

Patent No. 3,401,453. Divided and this application Mar.

22, 1968, Ser. No. 715,248

Int. Cl. B26b 19/04 US. Cl. 30-4332 7 Claims ABSTRACT OF THE DISCLOSUREElectric shaver or other appliance having a pair of parallel oscillatingshafts of rectangular cross section. Each of these shafts drives aseparate cutter or other driven member. A power unit is provided havingmotor means with a drive projection movable toward and away from theparallel shafts. A unitary bifurcated connecting rod interconnects theprojection and the two parallel shafts. This connecting rod issufficiently resilient to permit flexing so that no binding occurs.Spring means in the shape of a short handled multi-tined fork having thehandle portion secured to the rectangular shafts bias the cutters intoshearing engagement with the perforated comb. The comb is defined by twojoined arcuate perforated sections.

This application is a division of copending application Serial No.553,393, filed May 27, 1966, Patent No. 3,401,- 453 to Charles L. Bauerand assigned to the same assignee as the instant application. It relatesto apparatus for removing beards or face hair as well as hair on thearms, legs, and other portions of the human body, and is generallyreferred to as an electric dry shaver. More particularly, the presentinvention is in the nature of an improvement on the electric dry shaverdisclosed and claimed in Iepson et a1. Patent No. 3,196,539, grantedJuly 27, 1965, and assigned to the same assignee as the presentinvention. Moreover, certain features disclosed in the presentapplication are also disclosed in copending applications, both filed ofeven date herewith. Serial No. 553,510, Stahly et al., now United StatesPatent No. 3,447,058 and Serial No. 553,575, Bauer, now United StatesPatent No. 3,421,215, both assigned to the same assignee as the instantapplication.

Electric shavers of several different types are extensively employed bymany persons as the sole means of shaving. The type of electric shaverdisclosed in the above-mentioned Jepson et a1. patent has proven to beunusually 0 satisfactory for reducing shaving time while stillfurnishing a very satisfactory shave. Moreover, this shaver has beendesigned so that it may be held comfortably and conveniently in the handof the operator. As disclosed in this Jepson et a1. patent, the electricdry shaver is provided with a plurality of oscillating cutter bladesmounted on an oscillating shaft and cooperating with a perforated comband depending upon centrifugal force and spring means for moving thecutters into shearing engagement with the comb. The oscillating shaftcarrying the cutter blades is connected through suitable cranks and aconnecting rod to a rotary motor.

More recently a cutting head has been developed which employs a pair ofsuch oscillating shafts, each of which carries a plurality ofoscillating cutter blades cooperating with an arcuate portion of aperforate comb. It has been proposed to drive such a cutter headassembly from a rotary motor by means of a pair of connecting rods eachdriven from a respective one of a pair of eccentric projections eachextending from a gear driven by a motor pinion, as more fully describedin the above-identified Stahly et al. application. However, it will beappreciated that although the cost of any one driving arrangement may besmall, nevertheless electric dry shavers of this general type areproduced in very large volume, and the consumer market for the sale ofelectric dry shavers is highly competitive. Accordingly, it is desirableto provide an electric dry shaver which will compete favorably in priceon the consumer market. In this regard it is desirable to provide adrive means interconnecting a rotary motor and a pair of oscillatingdrive shafts which may be manufactured and assembled at a. minimum cost.

Moreover, in the design of a cutter head employing a pair of joinedarcuate comb surfaces, some difficulty may be experienced in maintaininga comparatively soft, flexible comb in the desired configuration.Further, in the consumer market it is important that the cutting bladesbe positively and economically secured to the respective cutter shaft sothat the shaver may be economically produced and perform reliably forthe ultimate user.

Accordingly, it is an object of the present invention to provide a newand improved electric shaver.

It is another object of the present invention to provide a new andimproved electric shaver which overcomes the difficulties mentionedabove.

It is another object of the present invention to provide an electric dryshaver having an improved cutting head.

A further object of the present invention is to provide an electric dryshaver of the type having a pair of oscillating cutter shafts providedWith improved connecting means drivingly interconnecting the motor withthe respective oscillating shafts.

A still further object of the present invention is to provide a new andimproved cutting head assembly for a shaver.

It is another object of the present invention to provide an electricshaver which may be economically manufactured and assembled and whichwill provide foolproof operation.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

For a better understanding of the present invention reference may be hadto the accompanying drawings in which:

FIG. 1 is an elevational sectional view through the cutter and easingportion only of an electric shaver embodying the present invention;

FIG. 2 is a fragmentary sectional view taken along line 22 of FIG. 1,assuming that FIG. 1 illustrates the entire shaver;

FIG. 3 is a fragmentary sectional view taken along line 33 of FIG. 1,again assuming that FIG. 1 shows the entire shaver;

FIG. 4 is a fragmentary somewhat enlarged sectional 'view taken alongline 44 of FIG. 1, again assuming that FIG. 1 illustrates the entireshaver;

FIG. 5 is a sectional view taken along line 55 of FIG. 4 assuming thatFIG. 4 shows the complete structure; and

FIG. 6 is a perspective view of the cutter shaft, blade supports, andblade biasing springs of the shaver according to the present invention.

The present invention is particularly adapted for use with an electricshaver of the type having a shaving head unit including a uniformlycurved comb and an elongated cutter blade adapted to be moved along theinner surface of the comb in shearing engagement therewith. One featureof the invention is particularly adapted for use with an electric shaverhaving a double shaving head unit, that is, of the type having a combdefined by joined arcuate surfaces and including a pair of oscillatingcutter shafts each carrying one or more cutting blades for moving theblades in shearing engagement with the comb.

In accordance with one feature of the present invention, the cuttershaft is rectangular. A rectangular shaft permits the use of an improvedblade support which may be of generally U shape having groove means inits bight portion to receive the shaft, and provided with aligned slotsin its outwardly extending legs for receiving the cutter blade.Additionally, there is provided an improved blade biasing spring whichmay be shaped like a shorthandled multi-tined fork having the handleportion thereof secured to the flat surface of the shaft in any suitablemanner as by welding, and having one of the tines each extending intothe path of a different one of the cutter blades.

In accordance with another feature of the present invention, there isprovided improved means for transfer ring power from a power unit todrive the pair of oscillating cutter shafts. It will be understood thatsuch oscillating cutter shafts, provided with an offset projectiondefining a crank, create a change in spacing between the cranks as theshafts oscillate. The shafts are driven from the power unit by a unitarybifurcated connecting rod defining a body portion connected to the crankor drive member of the prime mover, and provided with a pair of spacedarms each connected to a respective one of the cranks and sufiicientlyresilient to permit flexing of the arms relative to each other as thecutter shafts oscillate. To provide the necessary resilience to the armsof the connecting rod, the arms may be provided with reducedcross-sectional areas adjacent the body portion of the connecting rod,and the connecting rod may be built of suitable resilient material suchas nylon.

The single connecting rod with the bifurcated arms considerablysimplifies the connecting rod design providing an economicalarrangement. Moreover, the rectangular shaft cross section simplifiesthe connection to the shaft of both the blade supports and the bladesprings, thus reducing cost and simplifying assembly thereof.

Referring now to the drawings, the present invention is directed to anelectric shaver or shaving unit 20 which includes a casing 21 defined bya generally cup-shaped casing member 22 and a pair of end caps 24 and25, all preferably molded from a suitable plastic. 'For supporting themotor and cutter described hereinafter, there is provided a supportmember 26 which effectively closes the open top of the cup-shaped casingmember 22 to divide the casing .21 into a motor chamber below support26, generally designated as 27, and a cutter chamber above the support26 and between end caps 24 and 25, general- 1y designated as 28.Disposed within the cutter chamber 28 is a cutting head assemblygenerally designated as 29. Disposed within the motor chamber 27 is anelectric motor 30 secured to the underside of the support member 26.

Considering the motor 30 in more detail, it may be of a known type suchas disclosed in copending Jepson et al. application Ser. No. 322, 795,filed Nov. 12, 1963, now U.S. Pat. No. 3,349,263 and assigned to thesame assignee as the instant application. As illustrated, motor 30 is ofthe rotating armature type having a generally U-shaped stator member 33,the ends of the legs of the stator member 33 having a somewhat arcuateconfiguration defining 4 opposed pole pieces in a known manner. A fieldwinding 34 is carried on the bight portion of the stator member 33. Ahanger bracket 35, as shown in the above-mentioned Jepson et al.application, and a pair of U-shaped bail clamps 37 and a bail hanger 38hold the field structure in position relative to support 26.

The motor includes an armature 39 having an armature shaft 40 supportedin suitable self aligning spherical bearings in the manner described inthe aforesaid Jepson et al. application. One end of the armature shaftcarries a commutator assembly 45, while the other end thereof is thecrank end. Secured to the crank end of the armature shaft 40 is aneccentrically mounted crank pin 46.

In order that a power connection can be made to the shaver 20 fordriving the motor 30, the casing member '22 is provided with a recess oropening 53 in its end adjacent its bottom defining a receptacle openingfor receiving a power connection. A terminal board 54 within the casing21 of the shaver 20 carries a pair of terminal members 55 extending intothe recess 53 for engaging cooperating contacts of a power cord. Thelower end of the terminal board is keyed to an arm or projection 35a ofthe hanger bracket 35 so as to provide support for the terminal board54.

To provide a manual control for starting and stopping the motor 30, theterminal board 54 additionally supports a known electrical switch, showngenerally at 58. A manually operable switch knob 58a extends through anopening 24a in the end cap 24 to control the on-off condition of theswitch 58.

Referring now to the cutting head unit 29, it includes a comb 60defining a cutting surface. Comb 60 comprises a pair of joined arcuateperforated sections 66a and 60b, FIGS. 3 and 4, cooperating with a pairof substantially identical oscillating blade assemblies 61 and 62. Theoscillating blade assemblies 61 and 62 are adapted to be oscillatedthrough suitable driving means by the motor 30 at a suitable speed whichmay be in excess of 8000 cycles per minute. Each of the blade assemblies61 and 62 includes a plurality of cutters or cutter blades 63,individually referred to as 63a, 63b and 630.

For the purpose of supporting the cutter blades 63 for oscillation,there are provided a pair of oscillating cutter shafts 65 and 66, eachcarrying a pair of U-shaped supports 67 and 68, respectively, best shownin FIGS. 1 and 6. The cutter shafts 65 and 66 are of rectangular orsquare cross section. The bight portions of the blade supports 67 and 68are provided with slots 64 and 69, respectively, to receive and besecured to the respective shafts 65 and 66, while the legs thereofextend upwardly to define slotted blade support portions 67a, 67b, 68a,68b in a manner well understood in the art, the blades 63 beingreceivable in aligned slots in the support portions 67a, 67b, 68a and68b. The cutter blades 63 are effectively identical and may be similarto those fully described in either the above identified Jepson et al.patent or Jepson et al. application.

For the purpose of biasing the cutter blades 63 into shearing engagementwith the comb 60, there is provided for each blade support 67 and 68 atined spring member 70, best illustrated in FIG. 6. As illustrated eachspring member 70 is shaped like a short-handled three-tined fork havingthe short handle portion thereof secured to the respective shaft 65 or66 and with the three tines or spring fingers each extending into thepath of a different one of the blades 63 and consequently biasing theblades upwardly against the comb 60.

As best illustrated in FIG. 4, the comb 60 comprises a cutting surfaceformed of a very thin flexible material having a large number of hairreceiving openings. Since the cutting surface of the comb 60 is formedof relatively thin material, it tends to conform itself to the shape ofthe surface with which it is in contact and, therefore, must besupported by a suitable supporting structure or frame, generallydesignated at 74, comprising a plurality of parallel, double arcuateribs 74a, 74b, 74c, 74d, 74e, 741, 74g and 74h (FIG. 1) and spaced fromone another in a direction running along the longitudinal axis of thecutting blades 63. The end ribs 74a and 74h are effectively end framemembers and are somewhat stronger than the remaining ribs. The cuttingsurface portion of the comb 60 is suitably fastened at its outside edgesto the supportting frame 74 as by welding or other suitable means. Ifdesired, it may be removably secured. Moreover, in order to have thecutting surface follow the double arcuate contour of supporting frame 74with a central depressed portion (FIGS. 3 and 4) there is provided atubular comb tightener 75 which is held in place by U-shaped springretaining clips 76, best shown in FIG. 5. This comb tightener is similarto that disclosed and claimed in the abovementioned copending Stahly etal. application.

For retaining the comb 60 in shearing relationship with the rest of thecutting head assembly 29, there is provided a comb lock spring 78 (FIG.3) clamped in place between the bail hanger 38 and the support 26 by thebail clamps 37. As illustrated, the comb lock spring 78 terminates indownwardly extending pivot flanges 7 8a. A movable comb hinge plate 79has one edge releasably secured to one lower edge of the comb supportingframe 74. Moreover hinge plate 79 is hook-shaped as indicated at 79a onits other edge so as to make engagement with one of the downwardlydepending flanges 78a of the comb lock spring 78. A comb latch plate '80on the opposite side of the comb 60 from the hinge plate 79 is pivotallyrelated to the other pivot flange 78a on comb lock spring 78. Latchplate 80 is further provided with a centrally disposed latch member 8011extending through a suitable latch opening in the comb supporting frame74 thereby to latch the comb 60 in place as part of the cutting headassembly 29. The comb hinge plate 79 and comb latch plate 80 preferablyare similar to those more fully described in the prior mentioned Jepsonet al. Patent No. 3,196,539.

To support the cutter shafts 65 and 66 for oscillation, each shaft isprovided adjacent each end thereof with suitable resilient mountingblocks 82 preferably bonded to the associated shaft, which blocks may beof the type more fully described in a copending Jepson application, Ser.No. 410,115, filed Nov. 10, 1964-, now Pat. No. 3,244,916, and assignedto the same assignee as the present application. As in such copendingapplication, the mounting blocks 82 are clamped securely into positionbetween support member 26 and end caps 24 and 25, suitable recesses forsuch mounting blocks being provided. As illustrated, the shafts 65 and66 are each pro vided with integral crank portions 65a and 66a,respectively, (FIGS. 2 and 6) defined by otfset projections of theshafts.

For the purpose of converting rotary motion of the motor armature 39 tooscillating motion of the cutter shafts '65 and 66, there is provided inaccordance with the present invention an improved connecting rod 84(FIGS. 1 and 2). The connecting rod 84 is generally fork-shaped with abifurcated portion defining two crank arms 84a, 84b, each receiving arespective one of the crank portions 65a, 66a of the respective cuttershafts 65 and 66 and a body portion 84c. The body portion 840 receivesthe crank pin 46 and is held assembled with the crank pin 46 by means ofa hairpin type lock spring 85. Because of the variation in spacingbetween the driven ends of the oscillating shafts 65 and 66, the arms84a, 8417 on the connecting rod 84 must flex to accommodate thisvariation as the shafts 65 and 66 are oscillating. Accordingly theconnecting rod 84 is made of suitable resilient or springy material,such as molded nylon, and the arms 84a and 84b have a reducedcross-sectional area (FIG. 2) where they join with the body portion 840to provide the desired flex of the arms 84a, 8412.

For cutting longer hair such as trimming a moustache, sideburns and thelike, one of the end caps 25 carries a trimming cutter assembly 87(FIG. 1) driven by a projection from one of the cutter shafts 66. Thetrimmer cutter assembly 87 may be identical with that described in theabove mentioned Stahly et al. application and forms no part of thepresent invention. Accordingly the trimmer cutter assembly is notdescribed in the present application.

The twin cutter shafts driven by a single connecting rod simplifies thedrive of the double shaft head and provides a simple design which isinexpensive to manufacture. The single oscillating connecting rod canreplace two separate connecting rods, gears and pinion because of itsability to flex sufficiently to accommodate the variations in the shaftspacings of the cutter shafts as they oscillate. Moreover therectangular cross section of the cutter shafts and 66 permits the use ofsimple blade supports 67 of formed metal pieces which may be merely spotwelded to the supporting shaft, and further permit the simple tinedblade springs 70 to be readily spot welded or otherwise secured to thecutter shafts.

While there has been shown and described a particular embodiment of thepresent invention, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from theinvention in its broader aspects and it is, therefore, contemplated inthe appended claims to cover all such changes and modifications as fallwithin the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A cutting head for an electric shaver including a comb defined by twojoining arcuate sections having a plurality of parallel double arcuateribs spaced along the longitudinal axis of said comb defining asupporting structure for said comb, a perforated plate formed of thinflexible material secured to said ribs and conforming to the shape ofsaid ribs to provide a cutting surface comprising two adjacentperforated arcuate sections, a pair of blade supporting means eachincluding a cutter shaft provided with a plurality of blade supportsextending radially therefrom and spaced apart longitudinally thereof,the ends of each of said supports having at least one slot de finedtherein, a slot in one support aligned with a slot in another supportspaced longitudinally thereof and in a plane parallel to the axis ofsaid shaft carrying said supports, a plurality of elongated cutters insaid aligned slots, spring means biasing each of said cutters radiallyoutwardly, and means mounting each of said shafts for angularlyoscillatory motion with its cutters in shearing engagement with arespective one of said perforated arcuate sections.

2. The cutting head of claim 1 wherein said ribs define a centraldepressed portion, and wherein there is provided a comb tightenersecuring the comb around the contour of said supporting structure.

3. The cutting head of claim 2 wherein said retainer is cylindrical,open at its ends, including U-shaped spring retaining clips each havingone leg extending into a respective end of said retainer and its otherleg secured below said depressed portion.

4. The cutting head of claim 1 wherein said blade supports are providedwith a plurality of slots, the corresponding slots on each supportreceiving one of said elongated cutters.

5. The cutting head of claim 4 wherein said spring means are each formedlike a short-handled multi-tined fork having the handle portion thereofsecured to the respective cutter shaft, the tines of each spring meansengaging and biasing a different one of said cutters.

6. The cutting head of claim 5 wherein said cutter shafts are square incross section and spring means is welded to its respective cutter shaft.

7. A cutting head for an electric shaver including a pair of parallelpositioned cutter shafts each mounted for oscillating movement abouttheir respective longitudinal References Cited axes, cutter meanscarried by each of said cutter shafts,

and a comb comprising a pair of arcuate cutting surfaces UNITED STATESPATENTS cooperatively positioned relative to said cutter means,3,196,539 7/1965 Jepson 3043.9 said pair of arcuate cutting surfacesbeing defined by a supporting frame comprising a plurality of paralleldouble FOREIGN PATENTS arcuate ribs spaced along the longitudinal axisof the 932, 3/ 1955 ycomb and a thin flexible perforated plate securedat its outside edges to said frame and conforming throughout ANDREWJUHASZ Pnmary Examiner its surface area with said supporting frame. 10G. F. GRAFEL, Assistant Examiner

